Optimum Design of Cable Stayed Bridges Due to a Various of Loads

Youssef Agag, Mohamed Abou El-Saad, Mohamed El-Madawy, Mohamed El-Saman

Abstract: This research includes the optimal design of cable stayed bridges using the Parameter Space Investigation (PSI) method combined with LP? generator and the corresponding finite element program for design cable stayed bridge that meets the requirements of AISC "American Institute of Steel Construction" under the terms of strength, general and local buckling and develop a procedure for making optimal decisions on the Pareto set. The main research objective is to decrease the weight and the cost of bridge construction. Also, derive a main program to accelerate automation of calculations based on modern Finite Element software products. The study includes a comparison between four types of longitudinal ribs used in orthotropic steel deck. Many factors affect the optimization of bridges are taken into considerations. it was the number of ribs and floor beams, variations of rib thicknesses and floor beams, steel plate thickness and pylon thickness. The static analysis for each case due to self-weight of bridge elements and equivalent uniform traffic loads is carried out.

Keywords: Cable-Stayed Bridge, Finite Element, Orthotropic bridges, Pareto set, parameter space investigation (PSI) method